1. Field of the Invention
The present invention relates to an arterial-pulse-wave detecting apparatus which detects respective pulse waves produced from respective arteries of a plurality of portions of a living subject.
2. Related Art Statement
Since a pulse wave which is produced from an artery of a living subject includes various sorts of information related to the circulatory organ of the subject, the pulse wave is analyzed to make a diagnosis or judgment about arteriosclerosis, arteriostenosis, peripheral circulation, etc. However, since it is considerably difficult to identify a small change of shape or form of a portion of the pulse wave, a person may have failed to identify circulatory-organ-related information corresponding to the change of the waveform.
In the above-indicated background, it is possible to provide an arterial-pulse-wave detecting apparatus which detects respective pulse waves produced from respective arteries of a plurality of portions of a living subject, e.g., left and right portions located at respective positions symmetrical with each other with respect to a median line of the subject (because the circulatory organ is substantially symmetrical with respect to the median line), and which operates a display device to simultaneously display those pulse waves. However, if those pulse waves are displayed in a separated manner, it is yet difficult to identify a small change corresponding to an initial symptom of a disease, and accordingly a person such as a doctor may disadvantageously make a judgment influenced by his or her subjective factors.
It is therefore an object of the present invention to provide an arterial-pulse-wave detecting apparatus which detects respective pulse waves produced from respective arteries of a plurality of portions of a living subject and which allows a person to, or can itself, make an accurate judgment about a change or a difference of a form or respective forms of one or more of the respective pulse waves detected.
The above object has been achieved by the present invention. According to the present invention, there is provided an arterial-pulse-wave detecting apparatus, comprising a plurality of pulse-wave detecting devices which are adapted to be worn on a plurality of portions of a living subject, respectively, and detect respective pulse waves that are produced in synchronism with each other from respective arteries of the plurality of portions of the subject; a memory device which stores the respective pulse waves produced in synchronism with each other and detected by the plurality of pulse-wave detecting devices; and a pulse-wave-display control means for controlling a display device to display the respective pulse waves produced in synchronism with each other and stored by the memory device, such that the respective pulse waves are superposed on each other.
According to this invention, the pulse-wave-display control means controls the display device to display the respective pulse waves produced in synchronism with each other, detected by the plurality of pulse-wave detecting devices, and stored by the memory device, such that the respective pulse waves are superposed on each other. Thus, each one of those waveforms can be easily compared with the other waveform or waveforms. Therefore, a person such as a doctor can easily and accurately identify a small change of any one of those waveforms. Thus, the accuracy of inspection of the waveform of each arterial pulse wave is improved.
According to a preferred feature of the present invention, the pulse-wave-display control means controls the display device to display the respective pulse waves produced in synchronism with each other, such that respective minimal points of the respective pulse waves coincide with each other.
According to this feature, the respective pulse waves produced in synchronism with each other, are displayed such that respective minimal points of the respective pulse waves coincide with each other. Thus, a person can more easily and accurately identify a small change or difference of the waveform of any of the arterial pulse waves.
According to another feature of the present invention, the pulse-wave-display control means controls the display device to display the respective pulse waves produced in synchronism with each other, such that respective rising points of the respective pulse waves coincide with each other.
According to this feature, the respective pulse waves produced in synchronism with each other, are displayed such that respective rising points of the respective pulse waves coincide with each other. Thus, a person can more easily and accurately identify a small change of the waveform of any of the arterial pulse waves.
According to another feature of the present invention, wherein the pulse-wave-display control means controls the display device to display the respective pulse waves produced in synchronism with each other, such that respective amplitudes of the respective pulse waves are equal to each other.
According to this feature, the respective pulse waves produced in synchronism with each other, are displayed such that respective amplitudes of the respective pulse waves are equal to each other. Thus, a person can more easily and accurately identify a small change of the waveform of any of the arterial pulse waves.
According to another feature of the present invention, the apparatus further comprises an area-difference determining means for determining a difference between respective areas of the respective pulse waves displayed on the display device by the pulse-wave-display control means such that the respective pulse waves are superposed on each other, wherein the pulse-wave-display control means controls the display device to display the difference determined by the area-difference determining means.
According to this feature, the difference of respective areas of the respective pulse waves superposed on each other, determined by the area-difference determining means, is displayed on the display device. Thus, the difference of the two waveforms is quantitatively determined. In addition, a slow or overall change of a waveform that cannot be easily recognized in a conventional manner, can be easily identified according to this feature.
According to another feature of the present invention, the plurality of pulse-wave detecting devices comprise two pulse-wave-detecting devices which include respective portions adapted to be worn on left and right portions of the subject, respectively, that are located at respective positions symmetrical with each other with respect to a median line of the subject, and detect the respective pulse waves produced from the respective arteries of the left and right portions of the subject, and wherein the pulse-wave-display control means controls the display device to display the respective pulse waves produced from the respective arteries of the left and right portions of the subject, such that the respective pulse waves are superposed on each other.
According to this feature, the plurality of pulse-wave detecting devices detect the respective pulse waves produced in synchronism with each other from the left and right portions of the subject that are located at the respective positions symmetrical with each other with respect to the median line of the subject, the memory device stores the two pulse waves, and the pulse-wave-display control means operates the display device to display the two pulse waves such that those pulse waves are superposed on each other. Thus, a person can more easily compare the two pulse waves with each other and accordingly can more easily and accurately identify even a small change of either one of the two waveforms. That is, the accuracy of inspection of waveform of each arterial pulse wave can be improved. Since the two waveforms should be basically identical with each other, the change of each of the waveforms can be more easily identified.